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ISSN 1998-9539

Equilibrium between Two Degenerated Forms during Complexation of Novel Bis-crown Containing Bithiophene and Alkanediammonium Cations

Anastasia A. Kosmacheva,a Elena V. Lukovskaya,a@ Olga A. Fedorova,a,b Alla A. Bobyliova,a Yuri V. Fedorov,a,b Alexander V. Dolganov,b and Alexander V. Anisimova

aChemistry Department of Lomonosov Moscow State University, 119991 Moscow, Russia

bA.N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, 119991 Moscow, Russia

@Corresponding author E-mail: lukov@petrol.chem.msu.ru

 

DOI: 10.6060/mhc140375l

Macroheterocycles 2014 7(4) 365-372

 

Substituted oligothiophene possesses valuable physicochemical properties which make it possible to use in a field of molecular electronics as active semiconductor material in field transistors, as element of organic leds, in cells of solar butteries, in electrochemical devices. Supramolecular organization of oligothiophene compounds leads to facilitation of the processes of charge, electron and energy transfer and, consequently, extends the potentialities of designing new electrooptical systems. Crown ethers and their derivatives show unique and interesting selectivities towards different ions. Due to these ionophoric properties crown-containing compounds became very popular in chemistry of cation complexation. That led to design and construct practical systems with selectivity towards specific cations. Moreover, due to possibility to vary the length and structure of alkanediammonium cations it is easy to organize molecules into functional ensembles and vary their properties. In this study we synthesized 2,2’-disubstituted bithiophene ligand containing 18-crown-6-ethers. 2-Methylthiophene was used as an initial compound. Target product consists of ion-sensitive receptor, two thiophenes and two styryl fragments showing π-extended conjugation and can present electrochemical and optical properties. The process of complex formation with alkanediammonium salts +NH3-(CH2)n-+NH3 2ClO4- (An), n=8 (A8), 10 (A10), 12 (A12) was investigated. It was shown that crown ether fragments of dyes are able to bind diammonium cations producing equimolar complexes in acetonitrile solution. The stoichiometry of complexes was proved using spectrophotometric titration technique and ESI-MS data. Fluorescent analysis was also prepared to estimate influence of complexation on quantum yield. We proved alteration of electrochemical characteristics of the system during the process of complex formation using CVA technique. The structure of supramolecular ensembles was suggested using quantum-chemical calculations and proved by 1D and 2D NMR spectroscopy.

 

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